This invention relates generally to electrical contacts or terminals for removable attachement thereto of conductive elements.
More particularly, this invention relates to a female contact having a pair of opposed, cantilevered spring contact blades for use in association with male pin terminals.
Female contacts of the general type to which this invention is directed are conventionally used for the interconnection of printed circuit boards and other modular electrical components. Such contacts must be relatively inexpensive because of the large number used, must withstand repeated cycling with mating male pin contacts without loss of electrical continuity and ideally should be readily amenable to machine forming and use with automatic insertion machinery.
One of the problems encountered in the use of prior art contacts is in the overstressing, or bending to a set, of the contact blades during insertion or withdrawal of the male pins. This problem is particularly severe with contacts formed from a unitary piece of metal.
An approach taken in the prior art to avoiding overstressing spring contact blades is illustrated in U.S. Pat. No. 3,363,224. The contact described in that patent required either a coined or embossed tab area which overlies the free ends of cantilevered spring contact blades.
Brown in U.S. Pat. No. 3,663,931 discloses a contact having a pair of spring members tapering from a large cross-section to a relatively small cross-section at the connection pin engaging contact throat area with a pair of tab members limiting movement of the spring tips.
U.S. Pat. No. 3,270,251 illustrates a female contact having a pair of spring tongues formed in the contact sidewall with tab members overlying the free tongue ends to limit outward movement upon insertion of a male contact.
Another contact formed of sheet metal stock is shown in U.S. Pat. No. 3,362,008. This contact comprises a pair of inwardly bowed spring portions, each coined to a decreased thickness toward its centers and carrying an alignment tab medially located thereon.
Formation of female contacts from a blanked strip is illustrated in U.S. Pat. No. 3,269,805. Each contact unit blank comprises three parallel, transverse portions; the intermediate portion being substantially twice as wide as the outermost portion of each blank.